Modern medicine continues to confront controversies regarding the interaction of nature and nurture; that is, how significant are the contributions of environment or genetics to illness. Does the heart attack developing in the 48-year-old man devolve more from his increasing weight and fondness for french fries or from a genetic predisposition? Most doctors believe some combination of genetic vulnerability and environment inform disease.
Borderline Personality Disorder (BPD) is often associated with past emotional and physical trauma. It also appears to be linked to BPD and other disorders, such as depression, in blood relatives. Some individuals who have experienced severe trauma never exhibit BPD symptoms; and some who have been reared in healthy environments without crises demonstrate severe BPD pathology.
A recent study demonstrated how nature and environment interact on a molecular level. In a process known as epigenesis genes can be turned on or off by adding or subtracting molecules to the structure. Doctors from a university in Barcelona investigated status changes in the NR3C1 gene. This gene is involved in regulation of stress and systemic inflammation responses. A particular gene change, methylation, was tracked in 281 subjects with a diagnosis of BPD. A significantly positive correlation was noted between those patients who showed methylation status and childhood abuse. Furthermore, a positive correlation was observed between methylation and symptom severity. If more information about the environmental influences on genes develops, we may find more strategic treatments for many human diseases.